sequential gearbox

[cossyking]

as above whats a good 1 for a 4x4 cossy prefer standard ratio or higher 5th for top speed, has anyone got 1 thanks

[Kelv]

All of this talk of sequential boxes of late has had me trying to find out the differences in them all.

Found 7speed FFD, 6 speed FFD with active centre diffs, 6 speed H patterns which may be another FFD variant.
Ive started to get confused with it all

[cossiedavid]

you wont drive it fast enough to have one

[cosmagedon]

What power? R&D maby, plus you cant get the wrong gear when its a seq

Or ask mike how that dude was getting on with converting a lude to sequential

[SCS j1mbo]

All of this talk of sequential boxes of late has had me trying to find out the differences in them all.

Found 7speed FFD, 6 speed FFD with active centre diffs, 6 speed H patterns which may be another FFD variant.
Ive started to get confused with it all

Try going into ms numbers and gear ratios its even worse

We looked into gear ratios for dads to get the extra too speed and had I think 7 sheets of gear ratios, and input gears etc mental

[cossyking]

you wont drive it fast enough to have one

we see when your watching me in the distance lol

[Sunnysidebb]

All the Dog boxes from all the manufacturers will require regular re-builds. The dogs do not last very long and start to wear the corner edges making it difficult to engage gear.
Also early 5 dog, dog boxes were very hard on the palm of your hand, they were notchy and thumped your hand on every gear change. 6 Dog, dog boxes are much better but still require the regular maintenance and are still not suitable for a road car. You need to drive one before buying.
By saying 5 dog and 6 dog i don't mean the number of gears its the number of engagement dogs each gear has.

[ian sibbert]

Gearboxes – the history...lol

Sport Box - Early group A sierra - homologated box along with IIRC the Quaife 5 speed 3 and 6 tooth dog box..(horrible boxes)

MS90 - 7 Speed 'H' Pattern - Late sierra sapphire 4 x 4 box - early Group A escort cosworth..

MS92 – originally a 7 speed, can be converted to 6 Speed ‘H’ Pattern – Group A escort cosworth...all the FFD are year related



MS95 - 6 Speed 'H' Pattern Box - this was late Escort Group A - Early Escort WRC


These can have a Handbrake release (two master cylinders on the handbrake - passive as some like to call them) or Active Centre differential...

Dog gear (as Sunnysidebob said) you can see the 6 tooth engagement..



FFD did do a sequential version but it never really took off...there are still a couple about..
Bara then developed a sequential conversion for the FFD range and it is these that are the common FFD Sequentials



The last incarnation of gearbox used in the Escort WRC was an Xtrac 140, designed in conjunction with MSPORT then the license was sold to Dewitts..

A six speed sequential box used in the last Escort WRC cars....

[Tore_TJ]

Top info there

[Kelv]

Good info Ian.

What would a 6 speed FFD with an active centre diff be then mate?
Are the active diffs better/worse than the alternative variant?

[ian sibbert]

Kelv,

The last pic is a 6 speed MS95 with active centre...

Active centre is the most flexible and best performer in terms of rally use...the old passive centre diffs remain static in all conditions...the active can be programmed for the cycles a car goes through whilst manouvering through corners and on straights..

Pics of the centre diff activation when going through a hairpin..



As the car approaches the corner it is braking heavily and the differential will lock to the % set in the option Foot Duty. In the diagram this is fully locked to help slow the car down. The car then turns in and the driver pulls the hand brake. This puts the differential controller into Hand Duty % lock which is free in the diagram above to allow the rear wheels to break traction and the front wheels to roll. When the driver gets off the hand brake and begins to press the throttle the duty maps become active. In the example the duty map increases in lock with both throttle and rpm so full lock is archived at both full throttle and around 6500rpm.

This leads to a map shaped like this:



The active can also be programmed against wheel speed to become more open at higher speed to increase the cars top speed, if that makes sense....lol...

The old passive remains static, so this can lead to the car pushing on into and through corners, that essentially why in the day drivers had to drive the cars with a lot more commitment....looked good, but ultimately dangerous and slow...lol

[Kelv]

Blimey, It's getting quite in-depth then.

Cheers Ian

[Xen]

Thank you VERY MUCH Ian for all these information ! However, have you got a better picture of the schema showing the car taking the hairpin ? I cannot read what's written

[grcossie]

What about xtrac? Expencive stuff